Exemplary embodiments relate generally to organic light emitting display devices. More particularly, exemplary embodiments relate to organic light emitting display devices including a pixel region and a transparent region.
A flat panel display (FPD) device is widely used as a display device of an electronic device because the FPD device is lightweight and thin compared to cathode-ray tube (CRT) display devices. Typical examples of the FPD device are a liquid crystal display (LCD) device and an organic light emitting display (OLED) device. Compared to the LCD device, the OLED device has many advantages such as a higher luminance and a wider viewing angle. In addition, the OLED device can be made thinner because the OLED device does not require a backlight. In the OLED device, electrons and holes are injected into an organic thin layer through a cathode and an anode, and then recombined in the organic thin layer to generate excitons, thereby a light of a certain wavelength can be emitted.
Recently, a transparent OLED device has been developed that is capable of transmitting an image of an object (or target) that is located in the rear (or at the back) of the OLED device by including a transparent region and a pixel region. In this case, a transmissivity of a light incident into the transparent region may be decreased by a cathode electrode located in the transparent region. In addition, an IR drop (i.e., voltage drop) may be generated because the cathode electrode is thin. Thus, a definition (e.g., visibility) of the image of the object that is located in the rear of a conventional OLED device may be reduced due to the decrease of the transmissivity, and a uniform luminance may not be provided in the conventional OLED device because of the IR drop.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept, and, therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.